On the left side their is 3 green boxes with "x" inside of them. We can add them together (x + x + x = 3x). Their is also 2 red boxes with "-1" in them. We can combine them (-1 + -1 = -2).
On the right side their is 2 green boxes with "x' inside of them. We can add them together (x + x = 2x). Their is also 4 yellow boxes with "1" inside of them. We can combine them together (1 + 1 + 1 + 1 = 4).
Now, we have 3x + (-2) and 2x + 4.
We can combine them to be 3x + (-2) = 2x + 4 (Option D is the correct answer)
